rough idle

[timmy23]

I've got an '01 Silverado 4.8 that has recently gotten a rough idle. It seems to jump and shake every 10 seconds or so. It just hit 80k miles so is it the plugs or is there something else causing it?

[DEV1ST8R]

Wouldn't hurt to check the plugs+wires. Could also try a hardcore injector/engine cleaner.

[snoman]

Wouldn't hurt to check the plugs+wires.  Could also try a hardcore injector/engine cleaner.

 

Maybe but I would also check crank or cam position sensor too as it can send eratic data but not code as being bad and when they do it can cause the timing to very a lot at a idle sometime and greatly effect idle quality. Prblem is is that it is hard to detedt unless you use a scanner that can monitor the engine timing in real time. If you do and this is the problem you will see wide swings in timing when engine is idling funny. If this happens, you need to replace the sensors. Once again though I have seen this happen without throwing a code.